This is a proposal for the establishment of a Clinical Center for the study of heredo-retinal degenerations. These studies will attempt to place on a more quantitative basis the initial pathologic abnormality and the developmental course in certain of these diseases. At present, the physiological basis of most retinal diseases is poorly understood due to our inability to precisely define the locus of the abnormality in its earliest stages and the subsequent pathological sequence. We propose a series of non-invasive tests of retinal and pigment epithelial function to hopefully clarify this. By the use of fundus reflectometry, focal electroretinography, visually evoked cortical responses, psychophysical studies of retinal receptive field interactions, and spatial contrast sensitivity thresholds, we will attempt to provide detailed information on the early pathologic changes that characterize several forms of heredo-degenerative retinal disorders and to identify the specific retinal regions affected by the disease processes. Such studies, in which a more rigorous definition of the disease process in man is delineated, will enable the identification and development of animal models which are couterparts of the human disease and on which therapeutic approaches can be initiated.